Side Effects of Prostate Cancer Treatments Similar in Long Run - Study

Apr/02/2013

HealthDay News - For men with prostate cancer who are trying to decide between surgery or radiation therapy, new research shows that declines in sexual, urinary and bowel function do differ with each treatment in the short-term, but those declines tend to even out in the long run.

The study included more than 1,600 men treated for early-stage prostate cancer. Researchers asked them about their urinary, sexual and bowel health following either surgery to remove the prostate or radiation therapy.

Although the rates of health decline in these areas differed at two and five years after treatment, men reported similar declines regardless of their treatment after 15 years.

While men who underwent surgery experienced higher rates of urinary incontinence and erectile dysfunction two and five years later, men who received radiation therapy had higher rates of bowel urgency, or feeling like they had to pass stool but not being able to do so.

The study was published in the Jan. 31 issue of the New England Journal of Medicine .

"Our hope was that measuring patient-reported outcomes at a 15-year time point would provide patients and their physicians with a realistic picture of the prostate cancer survivorship experience," said study author Dr. Matthew Resnick, an instructor of urologic surgery at Vanderbilt University Medical Center in Nashville, Tenn.

Urinary, sexual and bowel problems are among the most common side effects of treatment for prostate cancer, Resnick added. Declines are probably due to a combination of the treatment and aging in general, and the side effects even out after 15 years.

However, the shorter-term differences could be enough to steer some men toward one treatment or the other.

"There isn't a one-size-fits-all approach; different men feel differently about the possibility of benefits and risks of treatment," Resnick said. For example, men who were already experiencing urinary incontinence might want to choose a treatment like radiation therapy because it was associated with lower rates of urinary problems in the short-term.

Surgery to remove the entire prostate, called radical prostatectomy, and radiation therapy are both recommended treatments for low- and medium-risk prostate cancer, according to the National Comprehensive Cancer Network guidelines.

However, these guidelines state that, for men with low-risk prostate cancer, watchful waiting -- closely monitoring the disease and treating it only if it changes -- is the best option.

It remains to be seen how men who opt for watchful waiting will fare in terms of their urinary, sexual and bowel health, especially in the long-term, Resnick noted.

Previous research has found doing watchful waiting for one year after diagnosis was associated with lower rates of urinary incontinence and sexual dysfunction, but higher rates of urinary blockage seven years later, compared to men who were treated immediately.

The current study involved 1,655 men who had stage 1 or 2 prostate cancer, which had not spread beyond the prostate. Men were diagnosed between ages 55 and 74 in 1994 and 1995, and most were treated in the year of diagnosis.

About 70 percent of the participants had radical prostatectomy, while the remaining 30 percent had external-beam radiation therapy, in which high-energy rays are directed from outside the body.

Treatment choice can vary based on a number of factors including age, prostate cancer stage and other diseases, Resnick said. The researchers took into account these differences when analyzing treatment outcomes.

The study authors asked the men about their urinary, sexual and bowel function before they had been diagnosed, as well as in the months following treatment. Participants also rated their own health in these areas.

Although there were declines after both treatments, men who received surgery reported sharper declines in urinary and sexual health, from a score of about 95 and 70, respectively, before surgery to about 60 and 20 in the months after.

"We would look at these changes and say they are meaningful," said Dr. John Wei, a professor of urology at the University of Michigan who was not involved in the study.

Even though their urinary and sexual health rebounded about a year after treatment, surgical patients were still six times more likely to have urinary incontinence and 3.5 times more likely to erectile dysfunction two years after treatment than radiation patients.

"The trajectory of the lines is different," Resnick said. "Obviously surgery is much more of an acute insult than radiation."

However, men who received radiation therapy reported greater early loss in bowel function, from a score of about 90 to 75. Although they went on to recover some function, the men who had surgery were 39 percent and 47 percent less likely to report bowel urgency two and five years later, respectively.

"I have been telling patients for years about these types of differences associated with prostate cancer treatment," Wei said.

This study gives a reference point when explaining these issues to patients, Wei said, adding that he applauds the authors for following the men in this study for 15 years.

By 15 years after treatment, the declines were in the same range for both treatment groups. Men reported a score of between 70 and 80 for urinary function, about 20 for sexual function and 80 for bowel function.

Nonetheless, "I would be somewhat careful in showing the results [of this study] to my patients," Wei said.

Intensive prostate cancer treatments are done differently today; for example, surgery can be done with a robot or with minimally invasive laproscopy using small incisions in the abdomen. Cancers also tend to be detected earlier when they are less aggressive, and so treatment could be less aggressive.

These differences could add up to lower side-effect rates, Wei said.

In the end, it comes down to what men decide with their doctors. Some men may worry about the invasiveness of surgery and opt for radiation therapy, whereas others might prefer surgery because they feel more comfortable knowing that their prostate has been removed and there is no chance of recurrence of prostate cancer, Wei said.